The present invention provides a device for manufacture of a product rolled continuously from a blank obtained by continuous casting into a grooved wheel.
The invention finds application more especially in the domain of transformation of non-ferrous metals or alloys, for example, for the production of wire in a transformation chain starting from the metal or alloy in the liquid state, cast in a grooved wheel and then rolled continuously.
Chains of continuous manufacture of this kind in accordance with the present concept comprise generally at the input a so-called four-wheel casting device illustrated in FIG. 1 (prior art) of the accompanying drawings which is a schematic elevation of the device. This device is followed by a number of roll stands. The casting device comprises a wheel 2 furnished with a peripheral groove and three return wheels 4, 5 and 7 around which runs a metal ribbon 3 forming an endless loop.
Two of the return wheels 4 and 7 arranged respectively above and below the grooved wheel 2 apply the ribbon partially to wheel 2, thus closing the casting groove over a portion of the circumference of wheel 2.
A third return wheel 5 is displaceable slightly by a jack 8 and ensures the tension of the ribbon, the linear speed of which in operation is equal to the circumferential speed of the casting wheel 2. There is thus contact without sliding of the ribbon against wheel 2. In the course of casting, the wheel 2 and the ribbon 3 are cooled forcibly by water. During manufacture of the product a casting nozzle 1, located above the wheel 2, pours molten metal or alloy continuously into the portion of groove closed by the ribbon, where it solidifies into a first blank which is moved directly into the rolling mills of the continuously working chain.
The temperature of the blank where it leaves the wheel is a very important factor to the quality obtained. If it is too high the blank may not be completely solidified and will not withstand the strains to which it is subjected on leaving the grooves. If, on the contrary, the temperature of the blank is too low metallurgical difficulties will appear in the rolling operations and the power necessary for rolling will increase considerably.
It is therefore important to be able to adjust this temperature to an optimum value which depends upon the metal or alloy being worked. Cooling of the metal is effected in the groove by thermal exchange from contact with the rim of the wheel which in turn is generally cooled by spraying with water. As the spraying is already being done with a strong flow it is not practically possible to act any further upon this flow in order to regulate the output temperature of the blank and in known installations the only action possible for modifying this temperature is to act upon the time of dwell of the metal in the groove, that is to say, to act upon the speed of rotation of the wheel. Any increase in speed translates into increase in temperature of the blank and vice versa.
But for a certain product, depending upon the nature of the metal or the alloy, the speed of production of the blank and of flow into the rolling stands downstream cannot vary in significant proportions. Excessive speed would lead to flaws in the cast and rolling defects while a low speed would reduce the industrial output of the installation. In other words, with every product there corresponds a relatively narrow field of temperature and speed leading to optimum manufacturing conditions. In known devices in which adjustment of temperature can only be effected by adjustment of speed it will not therefore be possible to obtain at the same time optimum temperature and speed and it would be necessary for that purpose to arrange a production chain strictly adapted to each kind of alloy.
The present invention has for its object an improvement in such a chain of production and more particularly to improvement of the continuous casting wheel, this improvement permitting use of the same chain of production for alloys of different compositions while providing in all cases optimum conditions of temperature and of speed of lamination.